This year marks the 200th anniversary of the Battle of Waterloo. Artists of the time – such as Turner and Byron – showed the full horror of its slaughter. Let’s not resort to fake empathy or cheap mawkishness now

Jonathan Jones: As the 25th anniversary of the fall of the Berlin Wall arrives, a British Museum exhibition is a reminder of the incredible richness of German arts and crafts – and shows us how history can have a happy ending